Screw driver attachment



Oct. 15, 1957 E. J. ONDECK 2,309,529

SCREW DRIVER ATTACK-WENT Filed Sept. 11, 1955 2 Sheets-Sheet 1 15 q J2 a! 1 IN VEN TOR.

2 sheetsfiSheet 2 E. J. ONDECK SCREW DRIVER ATTACHMENT Oct. 15, 1957 Filed Sept. 11, 1953 IN VEN TOR. $21 382 0 6160i United States Patent @flice 2,809,529 Patented Oct. 15, 1957 SCREW DRIVER ATTACHMENT Elmer J. (indeck, Brookfield, Ill.

Appiication September 11, 1953, Serial No. 379,549

Claims. (Cl. 74-202) This invention relates to a screw driver attachment, which is particularly adapted for use on a drill press or the like. It will be apparent from the following disclosure that a device of the character described herein can advantageously be used in other applications.

It is a general object of this invention to provide a simple, compact, and sturdy device for attachment to a drill press for driving and removing screws. It is a further object to provide a screw driver attachment of the character described which permits both the power and speed of the screw driver bit to be selectively varied. Another object is to provide a screw driver attachment which can be used both for driving and removing screws, and in which the direction of rotation of the screw driver bit can be readily reversed without disconnecting the attachment from the drill press or shutting off the drill press motor. A still further object is to provide a screw driver attachment equipped with control means having at least one driving and one removing position at which it can be set. In this connection, it is another object to provide a driving position in which the screw driver bit is operated at relatively high power and low speed, and a removal position at which the screw driver bit is operated at relatively high speed and low power. Still another object of the invention is to provide a screw driver attachment which does not operate to rotate the screw driver bit unless the bit is pressed downwardly against the screw, thereby making it possible to insert the bit in the slot of the screw with the drill press motor running. Further objects and advantages will appear as the specification proceeds.

This invention is shown in an illustrative embodiment in the accompanying drawings, in which-- Fig. 1 is an elevational view showing the exterior of a screw driver attachment constructed in accordance with this invention; Fig. 2, a vertical cross-sectional view showing the main elements of the screw driver attachment of Fig. 1 and taken on line 2-2 thereof; Fig. 3, a detail sectional view of the cooperating discs and roller employed in the attachment and taken on line 3-3 of Fig. 2; Fig. 4, another detail sectional view taken on line 44 of Fig. 3; and Fig. 5, a detail view showing the limit pin on the control shaft which operates to limit the pivotal movement of this shaft.

The principal operating elements are shown more clearly in Fig. 2. As seen in this figure, there is provided a rotatably mounted shaft 10 adapted to be driven in one direction. A disc 11 is fixed to the lower end of this shaft, and in the illustration given is integral therewith. Disc 11, therefore, can be rotated by shaft 10.

A second disc 12 is mounted with one side facing disc 11 at a spaced distance therefrom, and a second shaft 13 is fixed to the other side of disc 12 for rotation thereby. If desired, as shown, shaft 13 can be integral with disc 12.

As indicated in Fig. 2, and shown more clearly in Figs. 3 and 4, a control shaft 14 is pivotally mounted on an axis extending between discs 11 and 12, and a roller 15 is rotatably mounted on the inner end of control shaft 14 between discs 11 and 12. Roller 15 is arranged to frictionally engage the facing sides of the discs 11 and 12, as shown in Fig. 2. Preferably, this frictional engagement exists in at least two positions so as to permit the driving relationship between the discs to be varied. For example, one such position is illustrated by the position of the roller in Fig. 2 where the roller is shown in solid lines, and another such position is illustrated in the same figure Where the roller is shown in dotted lines. In the specific illustration given, the first position is the normal driving position of the attachment and the second position is the normal removing position of the attachment.

It will be noted that when the roller is in the position shown in solid lines in Fig. 2, that upper disc 11 must execute a number of rotations for each rotation of disc 12. Therefore, the driving relationship is one of high power and low speed, which is particularly desirable for driving screws. Similarly, when the roller is in the position illustrated by dotted lines in Fig. 2, it will be noted that lower disc 12 will execute a number of rotations for each rotation of disc 11. This position, then, is one of high speed and low power, which is a desirable driving relationship for removing screws.

As already indicated, the embodiment as illustrated in the drawings is particularly adapted for use on a drill press. For this use, the upper projecting end portion of shaft 10 is coupled to the driving shaft of the drill press by suitable means so that shaft It) will rotate in unison with the shaft of the drill press. Preferably, shaft 10 and disc 11 are retractable with respect to roller 1550 that disc 11 can rotate without contacting roller 15. In the specific illustration given, this is accomplished by having shaft 1i slidable within upper bearing 16 of end plug 17. Plug member 17 is mounted within the upper end of tubular casing 13, and the rest of the elements are mounted on casing 18. Therefore, when the attachment is suspended from shaft 10, as it would be when connected to a drill press, without any upward pressure being applied to shaft 13, sleeve bearing 16 moves downwardly on shaft 10 until its lower end is in contact with the upper side of disc 11. This has the eifect of retracting disc 11 with respect to roller 15, permitting disc 11 to rotate without contacting roller 15. However, when upward pressure is applied to shaft 13, as would be the case when the tip of screw driver bit 19 is forced against the head of a screw, this causes bearing 16 to move upwardly on shaft 10 until the lower face of disc 11 frictionally engages roller 15 and thereby drives disc 12 to operate screw driver bit 19. It will be apparent that this same cooperative relationship will be established regardless of the direction of rotation of bit 19 relative to shaft 10.

In the specific illustration given, the lower end of casing 13 is provided with a plug closure 20 having an opening 21 therethrough aligned with opening 22 in upper end plug 17, and also receiving a sleeve bearing 23 similar to upper bearing 16. Disc 12 normally rotates with its underside in contact with the upper end of bearing 23 and shaft 13 is journaled within bearing 23.

It is desirable to provide means for stabilizing the rotation of shaft 13. For example, in the illustration given, a cup-shaped cap 24 is threadedly connected to the lower end of easing 1.3 and provides an opening 25 aligned with opening 21. A sleeve bearing 26 is provided in opening 25 and shaft 13 is journaled therein. Above bearing an is a pin 27 which is passed through shaft 13 and projects outwardly from the side thereof to bear against the upper surface of bearing 26. Above pin 27 there is provided washers 28 and a compression spring 29 which has its upper end pressing against the lower end of bearing 21.

Any suitable means can be provided for permitting screw driver bits of various shapes and sizes to be can 3 nected to the lower end of shaft 13. In the illustration given, this is accomplished by providing screw driver bit 19 with a reduced end portion which is threadedly received within a recess 31 in the lower end ofshaft' 13. Bit 19 is held in fixed-relation to shaft '13 by means of collar 32 which is key'ed to both bit '19 and shaft 13, as illustrated in Fig. 2 at :33. A set screw 34 is provided in collar 32 to lock it in the engaged position with shaft 13 and screw driver bit 1-9.

Preferably, roller 15 is rotationally mounted on an axis which is offset from the pivotal axis of control shaft 14, as illustrated more clearly in Figs. -2 and 3. This has been foundto be of value in maintaining roller 15 at an established inclination or driving ratio during the operation of the attachment. For example, in the normal driving position for which roller 15 is shown in solid lines in Fig. 2, the forces acting on the roller are such as to cause it .to rotate in a counterclockwise direction as viewed in this figure. Similarly, in the normal removing position for which the roller is shown in dotted lines in Pig. 2, the forcesacting on the roller are such as to cause -it to rotate 'in a clockwise direction. Therefore, it is a simple matter to provide a stop pin on control shaft 14 to limit the pivoting of this shaft within the are between these two positions. For example, in the illustration given, casing 18 is provided with an outwardly-projecting sleeve 35 in which control shaft 14 is journaled with the use of a suitable bearing, if desired. As shown more clearly in Fig. 5, within sleeve 35 control shaft 14 can be provided with an outwardly-projecting pin 36 which extends into slot 37 and cooperates therewith in limiting the pivoting of shaft 14. In Fig. 5, pin 36 is shown bearing against one side wall of slot 37 as it would appear in driving position. It will be apparent that when this relationship is established further counterclockwise rotation of control shaft 14 cannot occur, and therefore this position will be stable, for the reasons explained above, even though shaft 14 is free to rotate clockwise.

If desired, a handle 38 can be provided on the outer end of control shaft 14 for the operation of this shaft. Also, it may be desirable to provide a finger extension 39 on handle 38 to assist the operator in sensing the position of roller 15, especially when intermediate positions are desired in which stop .pin 36 is not at one of its limits. In other words, the speed and power with which bit U is driven can be varied manually by the operator grasping handle 38 and holding this handle so as to maintain roller 15 in an intermediate position.

"As already indicated, any suitable means can be pro vided for rotatably mounting roller 15 in the inner end of shaft 14. In the illustration given, a forked support member 4% is provided, which straddles roller 15 and rotatably receives axle pin 41 upon which the roller is mounted. it will also be noted that in the illustration given, the inner faces of discs 11 and 12 are concave. This construction has been found to facilitate the frictional drive between the discs and to assist in promoting the operational stability of the attachment. It will be understood that roller 15 should be formed of rubber or other material adapted to frictionally engage the surfaces of discs 11 and 12.

While in the foregoing specification this invention has been described in relation to a specific embodiment thereof, it will be'apparent to those skilled in the art that the concept of this invention is susceptible to other embodiments, and that in such embodiments many of the specific detalis described herein can be varied widely.

I claim:

1. In a device of the character described, a rotatably mounted shaft adapted to be driven in one direction, a disc fixed to an end of said shaft for rotation thereby, a second disc having one side facing said first disc at a spaced distance therefrom, a second shaft fixed to the other side of said second'disc for rotation thereby, each of said shafts being spaced from the disc fixed to the other of said shafts, a control shaft pivotally mounted on an axis extending between said discs in a direction transverse to the axis of one of the other of said shafts, and a roller rotatably mounted upon the end of said control shaft between said discs with the plane of the roller substantially parallel to the axis of said control shaft, said roller being arranged to frictionally engage the facing sides of said discs at the same time in at least two positions for varying the driving relationship between said discs.

2. The combination called for in claim 1 in which the axis of rotation'of said roller is spaced from the pivotal axis of said control shaft said axis of rotation of said roller intersecting the axes defined by said shafts.

3. The combination called for in claim 1 in which the pivotal axis of said control shaft is also spaced from the axis of said one of the other of said shafts.

fl. In a screw driver attachment adapted for use on a drill :press or thelike, a tubular casing having an upper end and a 'lowerend, ;a plug secured in each end of said casing, said plugs having aligned openings, a shaft rotatably mounted in each ofsaid openings, s'aid shafts extending'outwardly beyond "said casing and terminating within said casing with their inner ends at a spaced distance apart, a disc mounted on the inner end of each of said shafts-for rotation in unison therewith, a control shaft pivotally gnounted in said casing with its inner end between-said discs-and its outer end beyond said casing for manual operation *of said shaft, and a roller rotatably mounted on the innerend of saidcontrol shaft between said discs, said roller being arrangedto frictionally engage the facing-sides of saiddiscs in at least two positions for varying the driving relationship between said discs.

5. The combination of'claim '4 in which in one of its positions said roller drives said second disc in the'same direction as said first disc, while-in the other of its positions this driving relationship is reversed with said second disc being driven 'in the opposite direction to said first disc.

6. The combination of claim 5 in which in said one position the driving relationship between said discs is one of relatively low speed and high power, while in said other position said relatibnsip "is one of relatively high speed and "low power.

7. The combination ofclaim 6 in which said roller is rotatably mounted on an axis offset from the pivotal axis of -sai'd='control shaft, and in wliich m'e'ans are provided fo'r limiting the pivoting of said control shaft in eaehdir'e'ction within a predetermined limited arc of movement.

8. The combinationofcl'aim 4 in which'the disc at-the upper end of said casing "is retractable "to a position at which it can rotate without'engag'in'g said roller.

9. In ade'v'iceof the character described, a rotatably mounted shaft adapted "to be driven in one direction, a disc fixed to an end of said shaft-for-rotation thereby,*a second disc having one side facing said first disc at a spaced distance therefrom, a second shaft fixed to the other sideof said second disc for rotation thereby, 'a'co'ntrol shaft pivotally mounted on anaxis extending between said' discs'in -a direction transverse 'to -'theaxis-of one of the other of said shafts, and a roller rotatably mounted upon the end ofsaid control shaft between said discs with the plane of the roller substantially parallel to'the axis of said c'on'tr ol shaftfs'aid rollerbein'g arranged to frictionally'engagethefacing sides of saiddiscs at the same time in'at least t'wo po'sitio'ns for varying the driving relationship between s'aid discs, said'roller in one of its positionsdriving said'second disc-in the same direction as said first disc, while intheoth'er of-its positions this driving relationship i's rev'e'rsed'with said second disc-being driven in theoppositedire'ction to said first disc.

10. ln a dev'ice 'of the character-described, a ro'tatably mounted shaft adapted to be driven in one directiorn a disc fixed to an endof said'sha'ft 'for'rotation thefeby, a second disc having one side facing said first disc at a spaced distance therefrom, a second shaft fixed to the other side of said second disc for rotation thereby, a control shaft pivotally mounted on an axis extending between said discs in a direction transverse to the axis of one of the other of said shafts, and a roller rotatably mounted upon the end of said control shaft between said discs with the plane of the roller substantially parallel to the axis of said control shaft, said roller being arranged to frictionally engage the facing sides of said discs at the same time in at least two positions for varying the driving relationship between said discs, said roller in one of its positions driving said second disc in the same direction as said first disc, while in the other of its positions this driving relationship is reversed With said second disc being driven in the opposite direction to said first disc, the driving relationship between said discs in said position being one of relatively low speed and high power, while in said other position said relationship is one of relatively high speed and low power.

References Cited in the file of this patent UNITED STATES PATENTS 665,355 Williams Jan. 1, 1901 1,049,756 Moore Jan. 7, 1913 1,187,263 Cochran June 13, 1916 1,239,401 Kelly Sept. 4, 1917 FOREIGN PATENTS 922,847 France Feb. 10, 1947 

